Relay



Jan. 6, 1942.

A. I. KASPER 2,269,206

RELAY Filed Feb. 20, 1941 Inventor 7 Anthony LKaspeh,

His tier-neg.

Patented Jan. 6, 1942 Anthony I. Kasper, Schenectady, N. Y., assignor toGeneral Electric Company, a corporation of New York Application February20, 1941, Serial No.

4 Claims.

This invention relates to relays and more particularly to improvementsin electromechanical primary relays for automatic regulators.

In order for an automatic electrical regulator to maintain the regulatedquantity substantially constant, it is necessary that it be controlledby a sensitive primary electroresponsive device. Many of these devicesare electromagneticallyoperated contact-making devices which in order tobe sufficiently sensitive must be constructed with practically the samecare and precision as is employed in the construction of sensitiveelectric meters. The moving parts must be light in Weight and small insize and consequently the contacts which are directly actuated by thedevice are often not suitable for controlling the current necessary foroperating the regulator, or operating the driving motor with which manyautomatic regulators are provided. It is, therefore, customary to employan auxiliary relay having a relatively low input which can safely behandled by the contacts of the primary relay and having relativelyrugged contacts which are capable of handling the current of theoperating motor. Furthermore, in many automatic regulators it isdesirable to provide a definite time delay between the response of theprimary relay and the operation of the regulator in order to preventunnecessary operation of the regulator in response to momentarydeviations of the regulated quantity from its normal value. This timedelay is usually provided by means of a separate time delay relay.

In accordance with this invention there is provided a novelelectromechanical relay which combines in one unit the functions of theprimary relay, the auxiliary relay and the time delay relay. It ischaracterized by relatively high sensitivity, the absence of anyvibrating or trembling engagement of contacts and the separateadjustability of the lengths of the time delay interposed in the raisingand lowering actions, respectively, of the regulator.

An object of the invention is to provide a new and improvedelectromechanical relay.

Another object of the invention is to provide a sensitive time delayrelay which is capable of handling directly the relatively large amountsof current required by the operating motor of motor-operated automaticregulators.

The invention will be better understood from the following descriptiontaken in connection with the accompanying drawing and its scope will bepointed out in the appended claims.

In the drawing Fig. 1 is a perspective view of the mechanism included inan embodiment of the invention and Fig. 2 is a circuit diagram of theelectrical connections of the invention when it is used in an automaticrheostatic generator voltage regulating system.

Referring now to the drawing, and more particularly to Fig. l, theprimary electroresponsive device consists of a solenoid magnet lmechanically connected by means of a wire 2 to a pivotally mounted leversystem 3. The pivotal mounting is a so-called cross-spring mountingconsisting of a pair of vertical blade springs 4 and a pair ofhorizontal blade springs 5 (only one of which is visible)interconnecting a rigid support 8 and a movable piece 1 forming part ofthe lever system. The effective pivot of this arrangement is along theimaginary line formed by the intersection of the substantiallyperpendicular planes in which the springs 4 and 5 lie. Attached to thepiece I is a movable arm 8 whose lower end is bent outwardly at rightangles to form a stop for a blade spring 9 carrying at its outer end anH- shaped piece Iii. The pull of the magnet I is counterbalanced by anadjustable weight II and the position of the entire lever assembly isbiased toward a neutral or normal position by means of a permanentmagnet I2 which is adjustably positioned with respect to pole pieces l3by means of a slot and eccentric arrangement l4 operated by a thumbscrew l5. The pole pieces l3 cooperate with a U-shaped magnetic memberl6 carried by the lever assembly.

The position of the Weight I l is determined by the desired normal valueof the regulated quantity, in proportion to which the magnet l isenergized, its location being such that the entire assembly is balancedwhen the magnet is normally energized. The pole pieces l3 are so locatedthat they tend to hold the normally balanced lever assembly in a normalor neutral position. This position is characterized by the H- shapedpiece Ill being midway between the arms of a U-shaped member H which iscontinuously reciprocated by a cam is on a cam shaft I9 which iscontinuously driven in the same direction by means of a motor 20. Thecam I8 is preferably made of fibre rather than metal so as to providequiet operation and the U-shaped member I! carries a roller type camfollower 2| for reducing wear and friction. The member I! is supportedin any suitable manner so as to confine its motion to the vertical. Forexample, it may be supported by means of a flat blade spring assembly,the outer end of which is shown at 22.

The main control contacts of the device are pair being limited in theoutward direction by means of rigid stops 25. The contacts are actuatedby pivotally-mounted yoke-shaped members 26 having downward extensions21. The arrangement is such that when the downward extensions are movedoutwardly from the center of the device (the center being definedgenerally by the vertical portion of the movable arm 8) the outer onesof the sets of contacts will be moved inwardly into engagement withtheir respective companion contacts. As all of the contacts are springmounted the contacts can move together after they come into engagementso that a considerable amount of additional outward motion of theextensions 21 is permitted after the contacts do engage each other. Onthe return or inward motion of the extensions 21 the contacts will staytogether until the springs carrying the inner contacts engage the stops25 whereupon a relatively quick break of the contacts is effected.

The time delayed closing of the separate sets of contacts in response tomovement of the lever assembly of the primary electroresponsive deviceaway from its neutral position is accomplished by means of complementaryratchet mechanisms 28 and 29, the former operating the raise contacts 23and the latter operating the lower contacts 24. These mechanisms aresubstantial duplicates, except that they have a right hand to left handrelation, and consequently their corresponding parts are given the samereference numbers. They each consist of a ratchet wheel 30 mounted forrotation on a shaft 3|. For the purpose of permitting adjustment of thetime delay, each wheel consists of two adjacent relatively rotatablegears 32 and 33, 32 being the inner wheel and 33 being the outer wheel,as viewed in the drawing. These two wheels are normally locked againstrelative rotation by means of a pinion gear 34 which is as wide as thetwo gears together and which consequently permits their rotation as aunit while preventing their rotation relative to each other.

For rotating each wheel 30 in the direction for causing closure of itsassociated set of contacts there is provided a pawl 35 pivotally mountedon a shaft 33 carried in a cage or frame 31 which is itself pivotallymounted on the shaft 3|. Similarly, for rotating each wheel 30 in theopposite direction for causing opening of its associated set of contactsthere is provided an opening pawl 38 pivotally mounted on a shaft 39carried in a frame 40 which is also pivotally mounted on shaft 3|. Foroperating each of the switches there is provided a pin 4| set into theinner face of the wheel 32 and so located that it will engage thedownward extension 21 of the switch operating yoke 23. For preventingcontinued rtation of each ratchet wheel after its respective switch hasbeen closed there is provided a pin 42 for engaging a backwardly andinwardly extending arm 43 on the closing pawl 35. This engagement inturn prevents the pawl from engaging the teeth of the ratchet wheel.

For operating the opening pawl 38 so as to rotate these ratchet wheels33 in the direction for opening their associated sets of contacts thereare provided frames 44 pivotally mounted on the shafts 3|. These framesare provided respectively with inwardly extending arms 45 and 46, eachof which is provided at its extremity with a cam follower for engagingrespectively a cam 41 and a cam 48 mounted on the cam shaft I9. Forpreventing each opening or resetting pawl 38 from continuing to rotateits Wheel 3|] beyond a definite angular position there is provided a pin49 set into the face of the outer half 33 of the ratchet wheel. This pinengages an inwardly projecting arm 50 on the frame 44, thus pivoting theframe 44 about the shaft 3| in such a direction as to prevent the cam 41or 48, as the case may be, from engaging its associated cam follower.

In order to prevent locking of the mechanism by the simultaneousoperation of the pawls 35 and 38 the frame 31 is provided with a gearsegment 5| for engaging a pinion gear 52 mounted on a spur shaft 53 towhich is attached a cam or trigger member 54 which is arranged 50 as toengage the extremity of an inwardly extending arm 55 on a lever 55carried by the opening pawl 38.

Adjustment of the amount of time delay is made possible by means of arotatable knob 51 mounted on the same shaft which supports the gear 34,this shaft being provided with an enlarged outer head against which aninner shoulder in the knob 51 is pressed by means of a spring 58 on theinside of the gear 34. The knob is larger in diameter than the gear 34but has a flattened portion which will permit the knob to be pushedinwardly when this portion faces the teeth of the ratchet wheel. Theknob 51 also carries a pin 59 for entering a. hole 69 in the outer faceof the outer ratchet section 33. When the gear is rotated so that thehole 60 is opposite the pin 59, which .is the position shown for theoperating mechanism for the raising contacts 23, the knob 51 may bepushed inwardly. This locks the outer part 33 of the ratchet wheel fromrotation and at the same time it unlocks the parts 32 and 33 because thegear 34 is pushed inwardly ahead of the knob 51 so that it disengagesthe teeth of the outer wheel 33. The inner wheel 32 may then be rotatedin either direction so as to change the angular relation between the pin49 on the one hand and the pins 4| and 42 on the other hand. Thisangular relation is indicated in terms of seconds of time delay by ascale on the inner wheel 32 which is visible through a window in thewheel 33 and which scale cooperates with an index point on the wheel 33.

The operation of the illustrated embodiment of the invention is asfollows: As shown, the lower contacts 24 are closed and the raisecontacts 23 are open and the block I0 has been moved to the left of itsneutral position, thus indicating that the energization of the magnet isbelow normal. In other words, the position of the parts indicates thatthe mechanism as a whole has just responded to a decrease below normalof the regulated quantity following an extended period in which thequantity was above normal. Assume now that the motor 20 is retatingcontinuously. Its direction of rotation is immaterial and we willassume, for example, that it is rotating in a clockwise direction. Thiswill cause the two ratchet wheels 30 to be rotated simultaneously stepby step in a counterclockwise direction, as viewed in the drawing. Therotation of the right hand ratchet wheel 33 is accomplished by means ofthe cam 43 which causes reciprocating motion of the frame 44 whereby theleft hand end of this frame engages the outer end of the pawl 38 on eachup stroke, thereby pivoting the pawl about the shaft 39, causing it toengage the teeth of the gear 30 and rotate this gear one notch or stepfor each revolution of the cam 48. This will almost immediately causethe pin 4| to disengage the extension 21 of the operating member for thecontacts 24 thereby opening these contacts. However, the step by stepcounterclockwise rotation will continue until the pin 49 engages theextension 55 of the frame 44 and raises it high enough to prevent thecam 48 from reciprocating its associated cam follower.

At the same time that this is taking place the closing pawl 35 of themechanism 28 for the raising contacts 23 is being reciprocated by meansof the left hand arm of the U-shaped member I! engaging the block l andpushing it upwardly into engagement with the pawl 35 during each upstroke of the member ll. The closing pawl 35 pivots about its shaft 35until its pivoting motion is limited by the opening in the frame 3'5through which it extends whereupon the entire frame and pawl are liftedas a unit thereby rotating its associated wheel 39 one step. At the sametime that the frame 31 is lifted the tripping arm 54 is raised by meansof the segment and gear 52 until it engages the extension 55 of the arm55 carried by the pawl 38. The frame 44 is being held out of engagementby the cam 4? by means of the pin 49 which through the arm 50 has raisedthe frame 44. However, as soon as the gear 36 starts rotating in thecounterclockwise direction the pin 49 permits the frame 44 to movedownwardly so that the cam follower on its arm 45 will be engaged by thecam 41. However, the resulting reciprocating motion of the frame 44 doesnot cause the pawl 33 to engage the teeth of the gear 35 because of theoperation of the arm 54 in simultaneously raising the inner end of theopening pawl 38 through the extension 55. Consequently, the ratchetwheel continues to rotate in the counterclockwise direction until pins41 and 42 engage arms 21 and 43, respectively. The engagement of pin 4|and arm 2'] causes closure of the raising contacts 23 in the mannerpreviously described while engagement of the pin 42 and the arm 43 looksthe closing pawl out of engagement with the teeth of the ratchet wheel30 so that continued reciprocation of the outer end of the closing pawl35 will merely reciprocate the frame 31 without causing furtherratcheting of the wheel 36.

If the block it is now returned to its neutral position the arms I? ofthe U-shaped member will slide up and down on opposite sides of theblock [0 without reciprocating this block and consequently arm 54 willno longer be actuated so that the reciprocating motion of the frame 54will then cause the opening pawl 38 to engage the teeth of the ratchetwheel 3i: and turn it step by step in the clockwise direction so assubstantially immediately to open the raise contacts 23. This actionwill continue in the manner previously described for the operatingmechanism 29 for the lower contacts until the pin 43 again engages thearm 53 and raises the frame 64 so as to cause the arm 45 to remove itscam follower from the cam 41.

Similarly, if the block In should be moved to the right of its neutralposition indicating that the energization of the magnet l is abovenormal the closing pawl 35 of the right hand mechanism will be operatedso as to rotate the ratchet wheel 38 step by step in a clockwisedirection in the same manner as has been previously described for theleft hand mechanism.

From the above description it will be seen that the operating mechanismsare in a sense lost motion connections between the motor or the meansreciprocated thereby and the contacts because it requires a considerableamount of motion or rotation of each of the mechanisms from theirinitial or reset positions until the mechanical connection is made bymeans of the pins 4| to the switch operating means for closing theseparate sets of contacts.

If desired, the ends of the arms of the member ll may be beveled, asshown, so that the greater the movement of the block 10 away from itsneutral position corresponding to greater departures from normal of thecondition to be regulated, the higher the block W will be raised on eachup stroke of the member ll. This will mean a greater angular rotation ofthe ratchet wheels for each step of rotation and consequently it willmean a shorter time delay. In other words, by means of such beveling thetime delay may be made to vary inversely with the degree of thedeparture from normal of the regulated quantity.

In Fig. 2 the operating magnet I is shown connected across the terminalsof a direct current generator 6! whose voltage is to be varied by meansof a motor-operated rheostat 62 which controls the field current of thegenerator. The direction of operation of the motor is selectivelycontrolled by the contacts 23 and 24. In this manner when the voltage isnormal the motor is at rest but if the voltage departs from normal thecontacts 23 and 24 will close after appropriate time delays dependingupon whether the voltage has risen above or fallen below normalwhereupon the motor 62 will rotate in the proper direction to cause therheostat to restore the voltage to normal. While for the sake ofsimplicity I have shown my invention in connection with a motor-operatedgenerator voltage regulator, it will be obvious to those skilled in theart that the motor for the motor-operated rheostat 62 could equally wellbe made to drive any other well-known form of regulator, such as atrans: former regulator of either the induction or step types.

While there has been shown and described a particular embodiment of thisinvention, it will be obvious to those skilled in the art that variouschanges and modifications can be made therein without departing from theinvention, and, therefore, it is aimed in the appended claims to coverall such changes and modifications as fall within the true spirit andscope of the invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In combination, an electroresponsive device having a movable member,a continuously operating motor, a two position circuit controller, alost motion coupling having a driven element for moving said circuitcontroller from one position to the other, a driving element for saidcoupling, and means under the control of said movable member forselectively operating said driving element in either direction by meansof said motor.

2. In combination, two pairs of normally open contacts, anelectroresponsive device having a movable member whose position isdetermined by the degree of energization of said device, said memberhaving a normal position corresponding to a normal energization of saiddevice, an irreversible continuously operating motor, wholly mechanicalmeans responsive to displacement of said member from said normalposition in one direction for causing said motor to close one of saidsets of contacts after a predetermined time delay, wholly mechanicalmeans responsive to displacement of said member from said normalposition in the other direction for causing said motor to close theother set of contacts after a predetermined time delay, and whollymechanical means for reopening either set of contacts When said memberis returned to its normal position.

3. In combination, two pairs of normally open contacts, anelectroresponsive device having a movable member whose position isdetermined by the degree of energization of said device, said memberhaving a normal position corresponding to a normal energization of saiddevice, an irreversible continuously operating motor, wholly mechanicalmeans responsive to displacement of said member from said normalposition in one direction for causing said motor to close one of saidsets of contacts after a predetermined time delay, wholly mechanicalmeans responsive to displacement of said member from said normalposition in the other direction for causing said motor to close theother set of contacts after a predetermined time delay, whollymechanical means for reopening either set of contacts when said memberis returned to its normal position, and separate means for independentlyadjusting the lengths of said time delays.

4. In combination, an electroresponsive device having a movable memberwhose position is determined by the degree of energization of saiddevice, a continuously operating source of reciprocating motion, aratchet wheel, a first pawl, said movable member serving in one positionthereof to connect said first pawl to said source of reciprocatingmotion and in another position to disconnect said first pawl from saidsource of reciprocating motion, said first pawl when connected to saidsource of reciprocating motion acting to rotate said ratchet wheel stepby step in one direction, a circuit controller, means for changing anelectrical property of said circuit controller when said wheel reaches agiven angular position, means for preventing said pawl from engagingsaid ratchet wheel when said angular position is reached, a second pawlfor rotating said wheel step by step in the opposite direction, meansfor connecting said second pawl to said source of reciprocating motion,means for preventing said second pawl from engaging said wheel whilesaid first pawl is reciprocating and for permitting said second pawl toengage said wheel when said first pawl is stationary, and means fordisconnecting said second pawl from said source of reciprocating motionwhen said wheel reaches a second given angular position.

ANTHONY I. KASPER.

